需要2个引用

using System.Net;
using System.Net.Mail;

 

            using (MailMessage mailMessige=new MailMessage())
            using (SmtpClient smtpClient=new SmtpClient(/*smtp服务器*/"smtp.163.com"))
            {
                mailMessige.To.Add(/*收件人地址*/"");
                mailMessige.Body=/*内容*/"Ni hao";
                mailMessige.From = new MailAddress(/*发送的地址*/"");
                mailMessige.Subject = "邮件标题";
                smtpClient.Credentials = new NetworkCredential("邮箱账号", "邮箱授权码");
                smtpClient.Send(mailMessige);
            }    

　　

 

有几点是要注意的

SMTP服务器的地址 和授权密码  要在邮箱的设置里面 找到